River ecological flow calculation method

Abstract

The invention discloses a river ecological flow calculation method. The method comprises the steps of collecting long-series day-by-day flow data of a river hydrological survey station, counting annual average flow, arranging the annual average flow as a data series according to a descending order no matter what the annual sequence is, calculating an experience frequency greater than or equal to the corresponding annual average flow in the series, and plotting an experience frequency point data graph on frequency grid paper; selecting a hydrological frequency distribution line type as PearsonIII type distribution; estimating initial estimation values of an average flow mean value and a deviation coefficient by using a moment method, calculating flow values corresponding to different accumulated frequencies, drawing a Pearson III-type theoretical frequency curve, judging a fitting condition of the Pearson III-type theoretical frequency curve and experience point data, and if the Pearson III-type theoretical frequency curve is matched with the experience point data, taking a parameter corresponding to the curve as an estimation value of an overall parameter; and finally, solving a flow value of 90% guarantee rate on the Pearson III-type theoretical frequency curve, namely the river ecological flow. The lower end or the upper end of the empirical frequency curve can be extended,and the defect of no actual measurement point data is overcome.

Description

technical field [0001] The invention belongs to the technical field of river ecological environment and relates to a method for calculating ecological flow, in particular to a method for calculating ecological flow of rivers. Background technique [0002] With the accelerated development and utilization of river water resources, river ecological and environmental problems have become increasingly prominent, and the concept of ecological flow has also been widely used. Due to the different perspectives and focuses of researchers, many concepts related to ecological flow have emerged, such as "aquatic ecological water demand", "aquatic ecological base flow", "minimum discharge flow" and "water demand for river ecological environment". In Australia and South Africa, the basic meaning of ecological flow is to maintain the ecological integrity and biodiversity of the river. In other words, ecological flow is the amount of water left for the river's own water needs. The definitio...

AI Technical Summary

Problems solved by technology

The hydrological method is fast and easy to operate, and does not require on-site measurement. The calculation is based on the historical runoff data of the hydrological station on the river, but its indicators have yet to be verified; the advantage of the hydraulic method is that only simple on-site measurement is required to obtain the hydraulics of the river. Data and ecological data, the disadvantage is that this method is only for the calculation of a specific section of the river, and does not consider the seasonal changes of river runoff; the ecological hydraulics method takes into account the change of river ecological effects and the comparison of social and economic benefits, but it needs A lot of human and financial costs, the implementation process is more complicated

The advantage of the habitat analysis method is that it matches the complete ecosystem functionality with the planning and governance of river basins. The disadvantage is that the implementation period is long, the cost is high, and a team of experts in various fields such as geography, ecology, and water conservancy is required, and it is not suitable for quick results.

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